HP500 Ignition Issues with Marine MSD Setup
 

I have been having issues with the port engine on my 03' 32 Sunsation. When I had the engines out 6 years ago I went with a complete MSD Marine Ignition setup including box, distributor and coil. Fast forward to this year and I had what I thought was battery issues. After a full charge in the Spring and the boat sitting for 4 - 5 weeks and battery switches off I went to the launch and found that the Port battery was dead. After using a jumper pack it started but just as I removed the battery pack it died like the key was turned off. I hooked the battery pack back up and restarted it and let it run for 2 minutes or so with the battery pack hooked up. Had no further problems for the rest of the weekend. Tried going out the next weekend and found the Port battery weak again after charging it. The engine would start and then die. With leaving a jumper pack hooked up for a few minutes it would continue running. We left the boat tied up and charger on for the evening and had no problems idling back to the launch the next day.

I decided to pull the batteries as they were going 4 years old and have them tested. The Port battery tested at 100 CCA's less than the Starboard battery, I decided to go ahead and get new batteries and install them. Started the port engine on the hose at home and no problems. Headed back to the lake for the weekend and had no issues Friday night or Saturday. Sunday morning the port engine started and then died after running for five or so minutes. Headed back to the dock to tie the boat up and after getting that done it restarted again. Died again after 5 minutes or so....in all of these instances it did not cough or sputter. We ended up testing the MSD coil and it was out of spec. We ended up replacing the coil and it seemed to be ok but I was not confident the problem was fixed however it ran that evening and following day.

This past weekend we headed to the launch and the same thing happened. Started the port engine and it died after running for 2 minutes. It restarted and again died after 2 minutes. After thinking more about this I have noticed that my Livorsi GPS Speedo that is wired to the Port Key switch has been going through the reset cycle when on plane. I had thought that it had something to do with the small battery in the satellite but now think it is losing power intermittently. I went ahead and replaced the key switch and tested the kill switch with an ohm meter. My plan is to head to the lake again and see if it happens again. If it does I will plan on seeing if when it dies if I can see a voltage drop on the purple wire on the key switch. I also made up a jumper wire to eliminate the kill switch if need be. I have checked all of the ground lugs on the back of the engine, cleaned the ground on the alternator and checked for loose connections everywhere. I know the MSD boxes are prone to failing however have always heard that when they fail they fail....no intermittent issues with them.

What other things should I try if what I have done does not correct the problem? Could the key switch have been shorting out causing the problem? Thanks in advance for your help and sorry for writing a book lol!

Swap msd boxes side to side mike

Sure as heck sounds like the port alternator.

This can be done but they are wired to the starter and a pain in the arse to get to. The ground is hooked to the ground stud on the back of the engine. I wonder if I could add a bullet plug or some other type of plug to where I could more quickly make the change moving forward for both the red power wire and ground? Any thoughts on this? I do have a new box though but just thought it was not the problem.

From what I gathered from your post is that you are actually using your boat. Congrats!

Thanks for the feedback! I typically run both battery switches on both. With that being the case do you still think the alternator could be the issue?

Does that connect both charging systems together ?

Edited above, brain and fingers did two different things.

Are charging systems tied together when you have both switches that way ?

Guess I am not sure how to answer the question. The switches are tied to one another....there is a cable that runs between both.They have the off, both, 1 and 2 selections on them.

I had a similar issue years ago when I had MSD. The problem was in the weather pack connector. The big one with several wires going to it.

Did you do a "draw test" to see if you have anything drawing power from the battery, when the key switch is "off"?

Hey Joe....no I have not done that test yet. I did just run out to the barn though and check the voltage of both batteries and the port battery was 12.38 and the starboard was 12.59. Wondering if like what SB said that it is the alternator. What I can tell you is that when hooking a jumper back to the port battery and leaving it on for a few minutes while running the engine would continue to run. Then after being charged in the slip overnight it was fine the next day. When the boat is at home I always turn the battery switches off. Thinking next step is to go to the pond and see what output there is. Thoughts?

What was wrong with the weather pack connector and what did you do to fix it? Did it cause a draw?

i would check alt output and main alt wire connector,i have seen the connector break.

Perform the checks above too.....but, running two alternators into the same connected system can fuk them up.

You need to seperate them.

One alternator per engine and that engine's batteries.

Boat manufacturers will let you tie them together so you can jump start one engine to the other without using jumper cables.

I normally run my switches on 1 and 2 , but have ran them both on "both" many times. My alternators positive wires go right to the starter main stud, I would assume yours do as well. I cant see running it that way hurting anything, heck, alot of heavy equipment stuff run dual alternators.

I do know the MSD boxes, are pretty voltage sensitive.The specs on the 6560 marine box, is 12 to 18V required. Where as, the daytona box, is 6 to 20 volt, and the cranes were 6 to 18 volts.

It could very well be a charging issue. The box gets its voltage requirement from the heavy gauge wires, so I don't think the purple wire having low voltage, would shut the box down, unless it had NO voltage, as in, a break in the connection, as that is used for a turn on lead only.

I'd probably start ONLY the troubled engine, and put a meter on the box's power source, and ground. The heavy gauge wires. With the engine running, you should see 13.5 plus volts there. If you don't get that, then check the voltage at the battery, and at the back of alternator.

A bad alternator not charging properly, allowing that sides battery to constantly drain down repeatedly, will kill the batterys life.

I do believe the stock alternator, NEEDS a 12 volt signal to the back of it, to charge. So, before you replace it, make sure the small wire going into the alternator, does in fact get power. If there was a break in that purple wire somewhere, the alt wont charge.

I had the same problem 3 years ago, I fought it all summer checking everything I could find, long story short,,my MSD would run or not run when it wanted due to internal problem inside the ignition box, I finally installed a new box and problem solved, has run perfect since then,, I wasted many hours looking for other problems that were not there.
Just saying that was my problem.
Good Luck

I have had an issue with the voltage regulator on the altenator go bad. It would charge and when it got hot it would stop charging. But everyone I would start the boat after sitting it would charge. My voltage gauge would go from 14 volts down to 12. It would jump back and forth when it tried to work while running. I could see it on my gauge I don't know if you can see anything like that or not. Or if both of your switches being on both would give you gauges a false reading. After that issue I got the altenator that charges after it revs past 1500rpm and doesn't have the built in regulator.

Put a screwdriver on the center back of the altanator and see if it is magnetic. If it is not , it's not charging